Plant Pathology MCQ Question and Answer | Agriculture MCQ Question

Photosynthesis is a Reduction process.
Photosynthesis is a process of reduction of carbon dioxide to carbohydrates, cellular respiration is the oxidation of carbohydrates or other nutrients to carbon dioxide.
During photosynthesis, plants take in carbon dioxide (CO₂) and water (H₂O) from the air and soil. Within the plant cell, the water is oxidized, meaning it loses electrons, while the carbon dioxide is reduced, meaning it gains electrons. This transforms the water into oxygen and the carbon dioxide into glucose.

India's rank in fertilizers consumption in the world is 3.
The main products offered by the fertilizer sector in India include nitrogenous fertilizers, complex fertilizers and phosphate-based fertilizers. Indian fertilizer industry ranks 3^rd in world production.
Consumption of fertilizers in India as per the 2019 census, is 29.37 million metric tons of nutrients.

In plants, water moves from a less negative to a more negative gradient.
Plants release water vapour into the atmosphere, which creates a negative pressure in the xylem, the layer of small vessels that brings water up from the root. If a plant has enough water, it opens its stoma, the pores under its leaves, to pull in carbon dioxide, which it photosynthesizes into sugar to fuel growth.
The root hair cells have carrier molecules on their cell membranes. These pick up the mineral ions and move them across the membrane into the cell against the concentration gradient.

Gypsum contains 29.2% Ca and 18.6% S.
Gypsum is a soft sulphate mineral composed of calcium sulphate dehydrate, with the chemical formula CaSO₄·2H₂O. Gypsum provides two of the secondary plant macronutrients, calcium and sulphur.
Gypsum is also formed as a by-product of sulphide oxidation, amongst others by pyrite oxidation, when the sulfuric acid generated reacts with calcium carbonate. Its presence indicates oxidizing conditions.

Zn is the micronutrient that is mostly deficit in Indian soil.
About 48.1% of Indian soils are deficient in diethylene-triaminepentaacetate (DTPA) extractable zinc, 11.2% in iron, 7% in copper and 5.1% in manganese.
The total Zn content in soil depends upon the parent rock, weathering, organic matter, texture and pH. The most quoted range of total Zn in normal soils in 10 - 300 mg kg^-1.

The yellow rust of wheat is caused by Puccinia striformis.
Wheat yellow rust, also known as wheat stripe rust, is one of the three major wheat rust diseases, along with stem rust of wheat and leaf rust.
Stripe (yellow) rust, caused by Puccinia striiformis f. sp. tritici (Pst), is a serious disease of wheat occurring in most wheat areas with cool and moist weather conditions during the growing season.
Yellow rust, or stripe rust, takes its name from the appearance of yellow-colored stripes produced parallel along the venations of each leaf blade. These yellow stripes are characteristic of uredinia that produce yellow-colored urediniospores.

Leveillula is an endoparasitic Powdery mildew fungus.
Leveillula taurica is an obligate fungal pathogen, from the phylum Ascomycota, which causes powdery mildew.
Under favorable climatic conditions, the chasmothecia open and release ascospores, which are wind-dispersed. The ascospores enter the host through its stomata, germinate, and colonize the host's tissues with their mycelia.
The pathogen then begins to produce its asexual conidia, either singly or on branched conidiophores. The conidia exit through the host’s stomata and serve as a secondary inoculum to spread disease after initial infection. It affects the host from the inside, thus it is endoparasite.

The causal organism of the bunchy top of the banana is transmitted by Pentalonia nigronervosa.
Banana bunchy top is a viral disease caused by a single-stranded DNA virus called the banana bunchy top virus (BBTV). It was first identified in Fiji in 1879.
Banana bunchy top virus (BBTV) is a plant pathogenic virus of the family Nanoviridae known for infecting banana plants and other crops. It is aphid transmitted.
It is known that Banana aphid (Pentalonia nigronervosa) transmits the virus from infected to healthy plants by feeding. Aphids feed on the plant phloem tissues by injecting their thin, flexible style into the epidermis of the plant tissue until it reaches the phloem of the leaves.

Among the given options, the factor which is not normally limiting in photosynthesis is Chlorophyll.
Chlorophyll is any of several related green pigments found in cyanobacteria and the chloroplasts of algae and plants.
Chlorophyll allows plants to absorb energy from light. Chlorophylls absorb light most strongly in the blue portion of the electromagnetic spectrum as well as the red portion.

The greatest producers of organic matter are phytoplankton of oceans.
Phytoplankton is the autotrophic component of the plankton community and a key part of ocean and freshwater ecosystems.
Phytoplankton obtains their energy through photosynthesis, as do trees and other plants on land. This means phytoplankton must have light from the sun, so they live in the well-lit surface layers of oceans and lakes.
The compartments influenced by phytoplankton include the atmospheric gas composition, inorganic nutrients, and trace element fluxes as well as the transfer and cycling of organic matter via biological processes.